Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a member of the mammalian subtilisin family of proprotein convertases. PCSK9 plays a critical role in cholesterol metabolism by controlling the levels of low density lipoprotein (LDL) particles that circulate in the bloodstream. Elevated levels of PCSK9 have been shown to reduce LDL-receptor levels in the liver, resulting in high levels of LDL-cholesterol in the plasma and increased susceptibility to coronary artery disease. (Peterson et al., J Lipid Res. 49(7):1595-9 (2008)). Therefore, it would be highly advantageous to produce a therapeutic-based antagonist of PCSK9 that inhibits or antagonizes the activity of PCSK9 and the corresponding role PCSK9 plays in various therapeutic conditions.